#include <iostream>
#include <cstdio>
#include <string>
#include <vector>
#include <queue>
#include <algorithm>

using namespace std;

vector<int> cd;

int getRes(int lb,int rb)
{
	int low=0,high=cd.size()-1;
	int res=-1;
	while(low<=high)
	{
		int mid=(low+high)>>1;
		int t=cd[mid];
		if(t<=rb&&t>=lb)
		{
			low=mid+1;
			res=max(t,res);
		}
		else if(t<lb)
		{
			low=mid+1;
		}
		else high=mid-1;
	}
	return res;
}
int main()
{
	int a,b;
	int n;
	cin>>a>>b;
	if(a>b) swap(a,b);
	for(int i=1;i*i<=b;i++) if(b%i==0)
	{
		if(a%i==0)
			cd.push_back(i);
		int t=b/i;
		if(a%t==0)	cd.push_back(t);
	}
	cin>>n;
	sort(cd.begin(),cd.end());
	while(n--)
	{
		int l,r;
		scanf("%d%d",&l,&r);
		cout<<getRes(l,r)<<endl;
	}
	return 0;
}
